Method of and apparatus for preparing compounds



C. A. PURDY June 2, 1,931.

METHOD 0F AND APPARATUS FOR PREPARING COMPOUNDS Filed Feb. 29. 1928 Nw,ww

. Pa/d/ N L Re@ \N Patented June 2, 1931 UNITED STATES PATENT OFFICECHESTER ARTHUR PURDY, OF OAK PAR-K, ILLINOIS., ASSIGNOR TO WESTERNELECTRIC COMPANY, INC., OF NEW YORK, N. Y., A CORPORATION OF NEW YORKMETHOD OF AND APPARATUS FOR PREPARING COMPOUNDS Application led February29, 1928.

This invention relates to a method of and apparatus for preparingcompounds, and more particularly to a method of and apparatus forpreparing insulatingV compounds.

It is the practice in some instances to impregnate electrical coilscomposed of insulated conductors with a protective covering ofinsulating material. Thus, certain types of electrical coils such asloading coils of the type employed in telephone systems are usuallyimpregnated with an insulating covering consisting of rosin and rosinoil compound. This compound has heretofore been prepared in someinstances by heating and occasionally stirring the lump rosin and therosin oil in a suitable tank over a long period of time, usually morethan forty-eight (48) hours. VThis method is obviously very slow andexpensive and requires a high degree of skill as well as very closeattention in order to insure a thorough mixing and drying of thecompound which is essential to secure the desired electricalcharacteristics.

The principal object of the present invention is to provide an improvedand inexpensive method of and apparatus for expeditiously andeiliciently preparing and treating compounds.

In accordance with the invention, an improved method of preparingcompounds consists in heating the raw ingredients to a predeterminedtemperature, simultaneously mixing the heated ingredients bycontinuously circulating them between a plurality of vheated tanks, anddrying the resulting compound or mixture by subjecting it to a vacuum.

The present invention may be employed to particular advantagein thepreparation of rosin and rosin oil compounds used for insulatingelectrical coils. In accordance with this embodiment of the invention,suitable quantities of the raw ingredients consisting of rosin and rosinoil are deposited in a heated tank iilled with previously preparedcompound, the compound thus displaced passing through a suitablestrainer into a second. heated tank. As additional Serial No. 258,123.

Vclearly understood from the following detailed description of aspecific embodiment thereof, reference being had to the accompanyingdrawing which schematically illustrates an apparatus embodying theinvention and which maybe employed in practicing the improved method inpreparing an insulating compound consisting of rosin and rosin oil. Itis to be understood, however, that the invention is not limited to thespecilc method or apparatus disclosed except as defined in the appendedclaims.

Referring to the accompanying drawing, an apparatus embodying thefeatures of the invention comprises a pair of tanks 10 and 11 of anysuitable construction and support-v ed upon vertical standards 12 and13, respectively. The tanks 10 and 11 are interconnected near the upperportions thereof by means of a horizontal pipe or conduit 14, one end ofwhich protrudes into the tank v10 and terminates in a suitable straineror filter 15. The material to be treated is deposited into the tank l0through a filling door 16 provided at the top thereof.

A conduit 17 extending 4from the top of the tank 11 is connected to asuitable vacuum pump (not shown). Vertically disposed conduits 18 and 19extending from the tops of the tanks 10 and 11, respectively, areconnected to a horizontally disposed conduit 20 which in turn isconnected to a two-way air valve 21. The airivalve 21 is connected to aVsuitable source of compressed air -(not shown) by means of aconduit-22.' Horizontally dspsed conduits," and' 24 'elt-lldng from thebottoms of the tanks and 11, respectively, are interconnected by atwoway valve 25. A pipe 26 leading from the valve terminates within athird tank or blow case 28 which is positioned below the tanks 10 and 11and is substantially smaller than them. A vertically disposed conduit 30extending upwardly from the top of the blow case 28 is connected to theair valve 21.

Pivotallysupported upon a bracket 32 secured to the top of the blow case28 is an L-shaped member 33. A pair of mercury contact switches 34 and35 of any suitable type comprising a sealed tube housing a pair ofspaced electrodes and a body of vmercury are carried by avertical arm 36of the pivoted member 33. The contact .switches 34 and 35 are disposedin opposed relation to each other so that .when one is closed the otheris open and vice versa. A horizontal arm 38 of the member 33 ispivotally connected at its end tov a. verticallydisposed rod 40 which isslidable in the top or cover of the blow case 28 and eX- tendsapproximately to the bottom thereof. Slidable on the rod 40 between apair of spaced stop collars 41 and 42 is a block 43 composed of anysuitable material adapted to float in the compound being prepared.

i One contact terminal 45 of the mercury switch 34 is connected to oneend of the vwinding of a solenoid 46 through a conductor 47. A contactterminal 48 of the mercury switch -35 is similarly connected to one endof the windingof a solenoid 50 vthrough a conductor 51. The oppositeends of both solenoid windings are connected to a line conductor 52 andthe other Vterminals 53 and 54 of the switches 34 and 35, respectively,are connected to a line conductor 55. The line conductors 52 and V55 areconnected to a suitable source of electrical energy (not shown).

As shown in the drawing, the solenoids 46 and may be mounted in a commonsupporting frame 5,7 which maybe supported in any suitable manner.`Pivotally supported intermediate its ends in a bracket58 secured to thesolenoid frame 57 is Va horizontally disposed bar 60 which is pivotallyconnected on opposite sides of its pivot to cores V61 and 62 of thesolenoids 46 and 50, respectively. One end of the bar 60 isconnected toan operating lever v63of the air valve 21 by means of a link 64 whilethe opposite end of the Vbar 60 is connected to an operating lever 65 ofthe valve 25 bymeans of a link66.

Mountedl within the tanks 10, 11 and 28 are spiral steam pipes 68, 69and 70, respectively, which may be connected in any suitable manner toasteam line so that the .compound is constantly maintained at apredetermined temperature.

The operation of the above-described apparatus is as follows: Assumingthat upon starting the operation of the apparatus the tanks 10, 11 and28 are empty, then it will be obvious that the iioat 43 will havedropped to the lower stop 42 on the rod 40 and will have caused the rod40 to move Adownwardly whereby the pivoted member 33 is turned in aclockwise direction thus closing the contact switch 34 and opening thecontact switch 35. As will be clearly understood by referring to thedrawing, the closing of the contact switch 34 establishes an electricalcircuit through the winding of the solenoid 46 and the opening of thecontact switch 35 opens a previously established circuit through thewinding of the solenoid 50. The solenoid 50 is thereby de-energizedwhereupon the energization of the solenoid 46 causes the latter toretract its core 61, thus turning the pivoted bar 60 in a clockwisedirection. This movement of the bar 60 causes an upward movement of thelink 66 and a downward movement of the link 64, thus turning the valveoperating levers 65 and 63 in a clockwise and counter-clockwisedirection, respectively, Vto the positions shown in full lines in thedrawing. When so positioned, the two-wayv valve 25 opens ythe passageVbetween the tank- 11 and the blow case 28 and closes the passagebetween the tank 10 andV theblow case, while the two-way air valve 21opens the air passage between the tanks 10 and 11 and the blow case V28and closes the passage between the compressed air line 22 and the blowcase.

After the valves 21 and 25 have been set as described above, the tank1() is filled up to the strainer 15 preferably with` previously preparedcompound. If this amount of prepared compound is not available therequired quantities of the rosin and rosin oilingredients are depositedinto the tank 10 wherein they are thoroughly mixed and heated as hasbeen the practice heretofore. In other words, it is to be understoodthat the outstanding advantages of the improved system and apparatus areparticularly effective when thetank lO'has been filled with thethoroughly heated and prepared case k28. As additional quantities of theingredients are deposited intothe tank 10, additional amounts of theprepared compound pass into'the blow case 28 and as the level of thecompound in the blow case rises, the float 43 moves upwardly along therod 40 until it strikes the upper stop 41 moving the rod 40 upwardly andthereby turning the pivoted member 33 in a counter-clockwise direction.This movement of the member 33 closes the contact switch 35 and opensthe contact switch 34 thus opening the previously established circuitthrough the winding of the solenoid 46 and closing the circuit throughthe winding of the solenoid 50. The solenoid 46 is thereby deenergizedwhereupon the energization of the solenoid 50 causes the latter toretract its core 62 thus turning the bar 60 in a counter-clockwisedirection. This movement of the bar reverses the valves 21 and 25, asshown in dotted outline in the drawing. The air valve 21 now closes theair passage between the blow case 28 and the tanks 10 and 11 and opensthe passage between compressed air line 22 and the blow case 28; and thevalve 25 opens the passage between the tank 10 and the blow case andcloses the passage between the blow case and the tank 11. The compressedair entering the blow case through the top thereof forces the compoundthrough the pipe 26, valve 25 and conduit 23 into the tank 10 throughthe bottom thereof. As the blow case empties, the float 43 movesdownwardly along the rod 40 and upon striking the lower stop 42 the rod40 is moved downwardly again reversing the valves 21 and 25 in themanner hereinbefore described. Meanwhile, the compound is constantlymaintained at a predetermined temperature by the steam pipes 68, 69 and70.

Additional quantities of the ingredients are deposited into the tank andthe above described cycle of operation is repeated until tanks l() and11 are both filled with the thoroughly mixed and heated compound, afterwhich the filling door 16 is closed and a vacuum is applied to theentire system through the conduit 17, the circulation of the compoundbetween the tanks 10 and 11 and the blow case 28 continuing in themanner described above until the compound is thoroughly dried. Whenthoroughly, treated the compound may be transferred from the tank 1linto a suitable reserve tank wherein it is stored until required foruse.

By the application of the present invention as described above, it hasbeen found that an improved compound is produced at a substantial savingof time and expense. The forced circulation between the tanks 10 and 11and the blow case 28 insures a thorough mixing of the ingredients.Furthermore, the use of a vacuum not only insures a thorough boiling offof the moisture but also provides a means for removing the vaporsproduced thereby.

Although the invention is herein illustrated and described in connectionwith the preparation of an insulating compound consisting of rosin androsin oil, it is to be understood that the novel features thereof arecapable of other applications within the scope of the appended claims.

What is claimed is:

1. A method of preparing rosin-rosin oil insulating composition, whichconsists in adding to a container containing a quantity of liquefiedmaterial solid ingredients of the material, liquefying the solidingredients, allowing said liquefied material to flow continuously intoa second container from which it flows to another container,automatically interrupting the flow of liquefied material into the lastmentioned container, causing the material in said last container to bereturned to the original liquefied material while the flow of thematerial continues from the first to the second container, andwithdrawing the material from the second container after liquefaction ofthe ma terials.

2. Apparatus for preparing insulating compositions including a pair oftanks, one of which is arranged to receive materials to be liquefied, aconnection between said tanks through which liquefied material flowsupon being displaced due to the addition of solid ingredients to theiirst tank, a third tank of smaller dimensions than the other tanksconnected with the two tanks, means in the third tank responsive to theHow of material from one of the other tanks, and an electrical meansoperated when a predetermined amount of liquefied material flows intosaid third tank for causing the liquefied material therein to bereturned to the larger tank into which the solid ingredients are placed.

3. Apparatus for preparing insulating compositions including a pair oftanks, one of which is arranged to receive materials to be liquefied, aconnection between said tanks through which liquefied material flowsupon being displaced due to the addition of solid ingredients to theiirst tank, a third tank of smaller dimensions than the other tanksconnected with the two tanks, means in the third tank responsive to theflow of material from one of the other tanks, electrical means operatedwhen a predetermined amount of liquefied material iiows into said thirdtank, and a pair of valves operated simultaneously by said electricalmeans for admitting air to saidthird tank and establishing a connectiontherefrom to the larger tank from which the liqueed material flowed tothe other larger tank.

In witness whereof, I hereunto subscribe my name this 15 day ofFebruary, A. D.

CHESTER ARTHUR PURDY.

